Many chemical reagents and chemical raw materials have their moisture contents stipulated in the product standards. It is evident from this fact that it is very important to control or dehydrate the moisture in chemical reagents and chemical raw materials.
As a dehydration method, it has been common to separate the moisture and the product by distillation or fractional distillation. However, in many cases, it is difficult to completely remove the moisture by distillation. Especially in the case of a substance azeotropically distilled with water or a substance having a strong affinity with water, it is difficult to adequately remove the moisture.
Further, there is a method available in which a solid powder such as molecular sieves or calcium chloride is added to let it adsorb water for dehydration. In this case, it is necessary to remove the solid powder having water adsorbed thereon. As a means for such removal, it is common to employ filtration, but in many cases, it is difficult to remove the solid having water adsorbed thereon.
For example, the moisture in a polyol of a usual grade used as a raw material for the production of urethane, is usually from 1000 to a few hundreds ppm. However, in a case of a grade where the moisture is particularly unwanted, the moisture is required to be not higher than 150 ppm. To remove the moisture in a polyol to a level of from a few hundreds ppm to not higher than 150 ppm, molecular sieves or other solid dehydrating agent, a tetraalkylsilicate or an oligomer obtained by the hydrolysis-dehydration-polycondensation thereof, is used at present. However, in the case of a solid dehydrating agent including molecular sieves, the filtration process is not easy, and in the case of the tetraalkylsilicate or the oligomer obtained by the hydrolysis-dehydration-polycondensation thereof, it takes a long time for dehydration (a few days at room temperature, or about one day at 60.degree. C.).
The present inventors have conducted extensive studies with an aim to develop a useful substance by the reaction of an amino group-containing compound with a silicate and have found that a novel composition obtained by the reaction of a certain specific silicate compound with an amino compound having hydroxyl groups, is an amino compound having a relatively low viscosity and a high boiling point, and such a composition readily reacts with water. The present invention has been accomplished on the basis of this discovery.